funny-falcon · July 31, 2012 09:52 · Jul 31, 2012 · Jul 31, 2012
diff --git a/gistfile1.txt → a copyright b/gistfile1.txt → a copyright
diff --git a/gistfile1.txt b/gistfile1.txt
@@ -0,0 +1 @@
+Original article: http://www.franzens.org/2011/10/writing-minimalistic-web-server-using.html
diff --git a/server.rb b/server.rb
@@ -0,0 +1,41 @@
+require 'rubygems'
+require 'eventmachine'
+require_relative './thin_http_parser.rb'
+
+# Freeze some HTTP header names & values
+KEEPALIVE = "Connection: Keep-Alive\r\n".freeze
+
+class RequestHandler < EM::Connection
+  def post_init
+    @parser = RequestParser.new
+  end
+
+  def receive_data(data)
+    handle_http_request if @parser.parse(data)
+  end
+
+  def handle_http_request
+    p [@parser.env, @parser.body.string]
+    keep_alive = @parser.persistent?
+
+    data = "OK"
+    send_data("HTTP/1.1 200 OK\r\nContent-Type: text/html\r\nContent-Length: #{data.bytesize}\r\n#{ keep_alive  ? KEEPALIVE.clone : nil}\r\n#{data}")
+
+    if keep_alive
+      post_init
+    else
+      close_connection_after_writing
+    end
+  end
+end
+
+host,port = "0.0.0.0", 8083
+puts "Starting server on #{host}:#{port}, #{EM::set_descriptor_table_size(32768)} sockets"
+EM.run do
+  EM.start_server host, port, RequestHandler
+  if ARGV.size > 0
+    forks = ARGV[0].to_i
+    puts "... forking #{forks} times => #{2**forks} instances"
+    forks.times { fork }
+  end
+end
diff --git a/thin_http_parser.rb b/thin_http_parser.rb
@@ -0,0 +1,88 @@
+require 'rubygems'
+# Uncomment this line if 'thin_parser' is not found
+# require 'thin'
+require 'thin_parser'
+require 'stringio'
+
+# Freeze some HTTP header names & values
+HTTP_VERSION      = 'HTTP_VERSION'.freeze
+HTTP_1_0          = 'HTTP/1.0'.freeze
+CONTENT_LENGTH    = 'CONTENT_LENGTH'.freeze
+CONNECTION        = 'HTTP_CONNECTION'.freeze
+KEEP_ALIVE_REGEXP = /\bkeep-alive\b/i.freeze
+CLOSE_REGEXP      = /\bclose\b/i.freeze
+
+# Freeze some Rack header names
+RACK_INPUT        = 'rack.input'.freeze
+
+# A request sent by the client to the server.
+class RequestParser
+  INITIAL_BODY      = ''
+
+  # Force external_encoding of request's body to ASCII_8BIT
+  INITIAL_BODY.encode!(Encoding::ASCII_8BIT) if INITIAL_BODY.respond_to?(:encode!)
+
+  # CGI-like request environment variables
+  attr_reader :env
+
+  # Unparsed data of the request
+  attr_reader :data
+
+  # Request body
+  attr_reader :body
+
+  def initialize
+    @parser   = Thin::HttpParser.new
+    @data     = ''
+    @nparsed  = 0
+    @body     = StringIO.new(INITIAL_BODY.dup)
+    @env      = {
+      RACK_INPUT        => @body,
+    }
+  end
+
+  # Parse a chunk of data into the request environment
+  # Returns +true+ if the parsing is complete.
+  def parse(data)
+    if @parser.finished?  # Header finished, can only be some more body
+      body << data
+    else                  # Parse more header using the super parser
+      @data << data
+      @nparsed = @parser.execute(@env, @data, @nparsed)
+    end
+
+    if finished?   # Check if header and body are complete
+      @data = nil
+      @body.rewind
+      true         # Request is fully parsed
+    else
+      false        # Not finished, need more data
+    end
+  end
+
+  # +true+ if headers and body are finished parsing
+  def finished?
+    @parser.finished? && @body.size >= content_length
+  end
+
+  # Expected size of the body
+  def content_length
+    @env[CONTENT_LENGTH].to_i
+  end
+
+  # Returns +true+ if the client expect the connection to be persistent.
+  def persistent?
+    # Clients and servers SHOULD NOT assume that a persistent connection
+    # is maintained for HTTP versions less than 1.1 unless it is explicitly
+    # signaled. (http://www.w3.org/Protocols/rfc2616/rfc2616-sec8.html)
+    if @env[HTTP_VERSION] == HTTP_1_0
+      @env[CONNECTION] =~ KEEP_ALIVE_REGEXP
+
+    # HTTP/1.1 client intends to maintain a persistent connection unless
+    # a Connection header including the connection-token "close" was sent
+    # in the request
+    else
+      @env[CONNECTION].nil? || @env[CONNECTION] !~ CLOSE_REGEXP
+    end
+  end
+end
Original file line number	Diff line number	Diff line change
		@@ -0,0 +1 @@
		Original article: http://www.franzens.org/2011/10/writing-minimalistic-web-server-using.html